iOS 11 File Provider fetchThumbnailsForItemIdentifiers method is not calling

Question

I implemented File Provider for new Files app on iOS 11. I want to show my files on remote, in Files app. I can enumarete items and show in Files app but iOS shows default thumbnail for images. So I need to show my own thumbnails for images.

fetchThumbnailsForItemIdentifiers:requestedSize:perThumbnailCompletionHandler:completionHandler:

Apple explain this method like following;

For local files, the system automatically provides thumbnails for supported content types, and calls a Quick Look Preview extension to get thumbnails for custom types.

However, the system cannot generate thumbnails for remote items. Instead, it calls this method to request thumbnails for items stored on a remote sever.

I implemented that method and make api call for the thumbnails. But that method is not called so i cannot show my own thumbnails for the images.

Why this method is not called? Is there anyone have an idea about that?

Thanks.

Answer 1

Seems you need to update the item's(ProviderItem) versionIdentifier property for the method to get called.The Apple documentation states that too. Was stuck in the same situation ;-)

Hope this helps!